Steam-accumulator plant



' Feb. 16 1926.

J. K. RUTHS ET AL STEAM ACCUMULATOR PLANT Original Filed July 10, 1922 Patented Feb. 16, 1926.

UNITED STATES PATENT OFFICE.

JOHANNES KARL RUTHS, OF DJ'URSHOLM, AND NILS PERSSON, OF STOCKHOLM, SWEDEN, ASSIGNOBS TO AKTIEBOLAGET VAPORACKUMULATOR, OF STOCKHOLM,

SWEDEN, A. CORPORATION OF SWEDEN.

STEAM-ACCUMULA'IOR PLANT.

Original application filed July 10, 1922, Serial No. 574,089. Divided and this application filed February 4; 1925. Serial No. 6,884.

To all whom it may concern:

Be it known that we, JOHANNES KARL Burns and NILS PERSSON, subjects of the King of Sweden, and residing in Djursholm,

Sweden, and Stockholm, Sweden, respectively, have invented certain, new and useful Improvements in Steam-Accumulator Plants (for which we filed application in Sweden, May 30, 1921) of which the following is a specification.

In stea'm plants equipped with accumulators it is old to cause the steam to pass through a motor such as a turbine or a reciprocatin engine in which power is extracted, a ter which the steam is led to low pressure consumers if all the steam can be used therein; or, when more steam is supplied than is needed by the low pressure consumers, the sur lus is led from the motor to an accumu ator to be stored, from which accumulator the steam is withdrawn for use when necessity demands. In such plants, the back pressure or extraction pressure of the motor, that is to say, that pressure to which the steam for the low pressure consumers expands in the motor is either always higher than the highest accumulator pressure or the same as that pressure and variable therewith. In the latter cases where the extraction pressure is substantially the same as and varies with the pressure in the accumulator, it is evident that the amount of power extracted in the motor is a function of the variable pressure in the accumulator.

In some instances, it has been found that it is possible to extract more power from the steam for the low ressure consumers if this steam can expand 1n the motor from the high pressure of the line from which it is taken all the way down to the pressure at which the low pressure consumers use steam and have this complete expansion irrespective of variations of pressure in the accumulator, and the surplus of steam generated over the momentary consumption is led in a path parallel to the path of steam passing through the motor to the accumulator from which steam is 'led to the low pressure con sumers when the demand on these consumers is greater than the supply afforded by the motor.

The present invention has for its purpose to provide means whereby the greater extraction of power in the motor as above outlined is accomplished and comprises an arrangement including one or more steam generators; a steam conduit system connected therewith; a steam accumulator, a motor, and one or more low pressure consumers connected in said conduit system; in combination with means to carry out the purpose set forth, involving a conduit leading steam from the accumulator to the low pressure consumers, a reducing valve or the equivalent in this conduit and means whereby steam extracted from the motor is led to this conduit at a point behind the reducing valve, that is, between the reducin valve and the low pressure consumers, and also involving certain regulating mechanisms necessary to the best realization of the invention, the function and advantages of which will be apparent as the descrlption proceeds.

This application is a division of our co pending application Ser. No. 574,089 filed July 10, 1922.

The accompanying drawing shows more or less diagrammatically an embodiment of our invention.

In the form of the invention herein disclosed steam is generated in steam generator A comprising one or more boilers. B is a conduit connected to the boilers to receive steam therefrom at boiler pressure. C is a consumer supplied by steam from conduit B through supply conduit 55, in the form shown, a non-condensing turbine, and exhausting steam through back pressure connection 51. Turbine C drives electric generator D connected to circuit E in parallel with other electric generators. K and G are parts of a conduit within the plant system which is at lower pressure than the main high pressure conduit B and steam generator A. The conduit K is herein termed an accumulator conduit. The pressure in this conduit varies with variations of pressure in the accumulator F which is connected thereto. G is the conduit from which the low pressure consumers such as drying cylinders of paper machines H are supplied with steam. G is herein termed low pressure conduit; Back pressure connection 51 is connected to conduit G. In conduit KG between accumulator conduit K and low ressure conduit G is provided a reducing va ve J, which receives steam from the accumulator conduit and delivers the same to the low pressure conduit.

According to the present invention the back pressure steam passes to the low pressure conduit G at a point after the reducing valveJ. By this arrangement it is possible to keep the back pressure. independent of the pressure in the accumulator F, and equal to the pressure of the low pressure consumers, although it is lower than the pressure in the accumulator. A valve M in conduit L connecting conduit 13 with conduit K, opens and allows steam to pass to the accumulator F when the pressure in the conduit B rises above a predetermined value.

Valves operating in this manner to increase the valve opening when the actuating pressure increases and to decrease the valve opening when the pressure decreases, we

term over-flow valves.

In the conduit N, also connecting conduit B with conduit K, is a reducing valve 0 which opens if the pressure which controls it should sink below a predetermined value. This valve operates to allow steam to pass towards the accumulator in certain cases if the accumulator is completely discharged. The small lines connecting the valves with the steam conduits indicate by which pressure the valves are operated.

In the operation of the plant steam is generated in steam generatorA and passes into conduit B. Here the steam divides itself into two paths, the one through conduit L and through or past the accumulator, through valve J, and thence to the low pressure consumers; the other path being through the supply conduit 55 to the motor C, through the motor C, through the back pressure connection 51 and thence, also, to the low pressure consumers. Thus it is seen that there are two parallel paths of steam leading from generator A to consumers H, the one having an over-flow valve M and a reducing valve J in it and an accumulator F connected therewith intermediate the overflow valve and the reducing valve and the other path having a motor in it.

A steam consumer P may be connected to conduit B. p c

When the steam consumption of low pressure consumers H is less than the amount of .more or less and decreases the flow of steam through motor C in a manner such that the pressure in low pressure conduit G is maintained constant. If by decreasing the valve opening of valve It the pressure in conduit B rises above a predetermined value, valve M opens and admits the surplus generated steam to the-accumulator F.

With only this arrangement however, if

more steam is required than can be supplied,

in conduit B, the pressure in conduit B would fall and the accumulator would not discharge until the pressure in conduit B is undesirably low. In order to prevent this drop of pressure in conduit B, to permit the peaks to be taken by the accumulator and to relieve the boilers of variations in demand and in pressure, a valve mechanism Q is provided in back pressure connection 51 which operates in the well known manner of overflow valves by opening when the actuating pressure rises above a predetermined value and operating in a range above this value to increase the valve opening on rise of pressure and decrease the valve opening on decrease of pressure. Valve Q, is operated by pressure in conduit B and acts to maintain the same constant.

In order to explain more thoroughly the operation of the plant, assume that there is at first a decrease of consumption in the low pressure consumers whereby the pressure in conduit G rises. The rise of pressure causes a decreased flow through valve R by closing the same somewhat. This increases thepressure in conduit B so that valve M opens and admits the surplus generated steam over the momentary consumption to the accumulator.

Now suppose the low pressure steam consumption increases. The pressure then decreases in conduit G so that valve R opens. If, however, valve R- is open and more steam is needed, the pressure in conduit B will fall (other factors remaining equal). Valve M then closes and then valve Q decreases the flow through the motor. This decreases the pressure in conduit G so that valve J opens and admits steam from the accumulator to the low pressure consumers. Valve Q begins to close its valve opening at a pressure somewhat lower than that at which valve M is closed.

S represents a speed responsive device normally inoperative but coming into operation if the motor speeds up above normal.

If consumer P is connected and its consumption is variable it is evident that pres sure variations will arise the-efiect of which will be evident from the above description as will also the fact that all variations will be taken care of wherever and whenever they occur in the plant so that the boilers can generate a quantity of steam corresponding to the average consumption of the plant at constant pressure and praeticall constant pressures can be maintained in all conduits except those immediately connected with the accumulator.

The arran ement herein disclosed has the particular a vantage that an ordinary turbine su plied-with a regulating control operated by the back pressure or extraction pressure can be adapted to combination with an accumulator in the manner herein set forth by merely adding an overflow valve 0 erated by the ressure in the turbine suppy line and wit out changingthe existing regulation.

The showing of valve R on the drawing is to be understood as diagrammatically indieating any mechanism controlling supply of steam to the motor D, and operating in the manner set out.

Various changes in parts and arrange ments of the same falling within the scope oi the invention will be obvious to those skilled in the art to which this invention be longs. Obviously, many parts may be added to the plant shown without departing from the spirit or scope of the invention. The drop of pressure in the valve Q is less when the same. is placed afterthan before the turbine.

Having thus described our invention in accordance with the provisions of the patent statutes, what we desire to secure by Letters Patent of the United States is:

1. In combination, a steam generator, a conduit system connected therewith, a steam motor connected in said conduit system, a supply conduit in said conduit s stem to supply steam to said motor, a secon conduit in said system, connecting means conducting steam from said motor to a point in said second conduit, an accumulator connected to said second conduit at a second point, a reducingvalve in said second conduit between said points, automatic pressure operated means to conduct steam in parallel to said motor from said generator to said accumulator, a consumer connected to said second conduit, a valve controlling supply of steam to said motor and operated in response to the pressure in said connecting means and a valve in said connecting means operated in response to the pressure in said supply conduit.

2. In combination, a high pressure steam conduit, a steam motor, a supply conduit conducting steam from said high pressure conduit to said motor, a low pressure eonduit, a connection leading steam from said motor to said low pressure conduit, an accumulator, an accumulator conduit connected therewith and adapted to deliver steam to said low pressure conduit, a reducing valve controlling the delivery of steam from said accumulator conduit to said low pressure conduit, means to conduct steam from said high pressure conduit to said accumulator parallel to said motor, a valve controlling said means operated in response to pressure in said high pressure conduit so that it closes when the actuating pressure falls below a predetermined value, a valve in said supply conduit operated in response to pressure in said connection so that it opens when the actuating pressure falls, a valve in said connection operated in response to the ressure in said supply conduit, so that it c oses when the actuating pressure falls, the second mentioned valve being set to close at a higher value of the actuating pressure than the last mentioned valve.

3. In combination, a steam generator, a consumer, two parallel paths of steam from said generator to said consumer, the one containing an overflow valve, and a reducing valve and having an accumulator connected between said valves, the other containing a motor, a valve mechanism controlling the flow of steamto the motor in response to the pressure of steam leaving the motor and a valve mechanism controlling the flow of steam from the motor in response to the pressure of steam at a point ahead of the motor in the path of steam containing the motor.

4. In combination, a steamgenerator, a motor, a su ply conduit therefor, a low pressure eon uit, a consumer sup lied withsteam from said low pressure con uit, a connection leading steam from said motor to said low pressure conduit, an overflow valve in said connection controlled by the pressure in said supply conduit, a reducing valve mechanism in said supply conduit controlled by the pressure in said connection, an accumulator, an accumulator conduit connected therewith, a reducing valve receiving steam from said accumulator conduit and delivering the same to said low pressure conduit, a conduit conducting steam from said generator to said accumulator and an overflow valve in the last mentioned conduit.

5. A source of high pressure steam, a source of low pressure steam, a first consumer, a second consumer, a reducing valve, means to conduct steam from said source of low pressure steam to said second consumer through said reducing, valve, means to conduct steam from said source of high pressure steam to said second consumer through said reducing valve, mechanism responsive to pressure in the source of high pressure steam to control flow through the last mentioned means, means to conduct steam parallel to said reducing valve from said source through said first consumer and to said second consumer, reducing valve mechanism controlling flow of steam to the first consume1 in response to pressure of steam leaving the first consumer, and overflow valve mechanism controlling flow of steam from the first consumer in response to pressure in the source of high pressure steam. 10

In testimony whereof we aflix our signatures. JOHANN ES KARL RUTHS.

NILS PERSSON. 

